1. Field of the Invention
The invention relates to atomizers, and more particularly to a nozzle replaceable atomizer with automatic abnormality detecting function that can automatically detect abnormal operation for a user to easily determine whether its spray head has to be fixed or replaced, thereby providing convenient management and maintenance for normal nebulization.
2. Description of Related Art
As MEMS (Micro Electro-Mechanical System) technology has advanced rapidly, the recently developed drug dispensing atomizers are made to generate extremely fine mist of medicine particles that is helpful to enhance inhalation and curative effects. These atomizers are made portable and thus are convenient for various patients to use. However, a spray head on the known atomizer tends to get clogged after long-term use and its cleaning is troublesome. As an improvement, atomizers with replaceable spray nozzles have been proposed for ensuring not only normal nebulization, but also use hygiene and safety.
The atomizers with replaceable spray nozzles, however, have their challenges. For example, one technical issue encountered when it comes to replacement of spray nozzles is about the piezoelectric enabling element of the spray nozzle. Since different materials and different porous metal nozzle plates have different (inconsistent) vibrational properties, it is essential to have the piezoelectric element properly adjusted in terms of operating frequency, or normal nebulization is impossible. For addressing this issue, a known scheme proposed is about directly getting feedback signals from the piezoelectric element (by using, for example, a vibration sensor) and accordingly performing frequency adjustment, yet the feedback signals are usually not accurate enough and likely to lead to fault detection. As a further improvement, a disclosure discloses a nebulizing device with a detachable spray nozzle, wherein variable resistance or variable capacitance (to be manually adjusted) is used to properly set the operating frequency for the piezoelectric element. Nevertheless, in practical use, users (consumers) of the atomizer when doing adjustment without the aid of any electric detecting instruments has no scientifically-proven data as reference and can hardly identify the optimal operating frequency. Given the required manual adjustment and uncertain adjusted results, this known approach is somehow inconvenient.
Another disclosure discloses an adjusting method and structure for resonance frequency of a demounting type spray head of an atomizer. It implements microcomputer frequency tracing technology to automatically align the operating frequency the piezoelectric element with its resonance frequency, and effectively eliminates the inconvenience and inaccuracy related to manual adjustment. The frequency tracing technology can fix the newly assembled spray nozzle to the aligned operating frequency, and secure the piezoelectric element to work with this frequency throughout all sequent spray sessions. However, in the event that the piezoelectric element or the nozzle plate becomes unable to atomize the liquid it sprays to the desired level, the atomizer provides no means to detect this situation and readjust the operating frequency of the piezoelectric element accordingly.
It is known that good medicine inhalation and curative effects depend on the fine mist of atomized medicine generated by atomizers. As an untrained user is usually unable to tell the subtle difference between the original and degraded nebulization by his/her bear eyes, the deterioration can remain undetected until more significant difference occurs and this means a long period of ineffective or poor inhalation treatment has lapsed. For example, a nozzle plate is gradually clogged over a long period opposite to being blocked to the extent that it shows obvious abnormality instantly. Generally, once the nozzle plate is clogged, even slightly, the frequency on which it combines with the piezoelectric element begins or has begun to change, and the original operating frequency fixed by the microcomputer may become or have become no more optimal for resonance, leading to deterioration of nebulization.
The deterioration increases and becomes more obvious as the nozzle plate is clogged more seriously. When the nebulization is too poor and it is found that the spray nozzle has to be replaced, the piezoelectric element may have worked with a non-resonant frequency for a considerable period. Consequently, the user using this atomizer receives little or no treatment through inhalation during this period. Therefore, it would be desired that the atomizer can keep checking whether the operating frequency of its piezoelectric element reaches resonance throughout operation and timely readjust the operating frequency to compensate any deterioration. Additionally, in an atomizer capable of detecting whether its piezoelectric element works on resonance, as long as the abnormality of the piezoelectric element related to misalignment to the resonance frequency is not caused by serious deformation, breakage, or manufacturing/assembling defects of the piezoelectric element and/or the nozzle plate, it can be corrected by using a microcomputer in the atomizer to use frequency tracing function to realign the operating frequency with the current resonance frequency, so the atomizer can always works normally. Thus, it would be desired to have an atomizer whose nozzle is replaceable. The atomizer preferably uses frequency tracing technology as a breakthrough to address the need of adjustment for resonance, and is capable of detecting whether its piezoelectric element is operating in a resonant state.